Acoustic liquid level measuring apparatus

Abstract

An acoustic liquid level detector system includes, a) a first acoustic wave guide; b) an acoustic wave transmitter and an acoustic wave receiver operably associated with the first acoustic wave guide to transfer acoustic waves between, i) the acoustic transmitter and receiver; and ii) the first acoustic wave guide; c) a second acoustic wave guide; d) an angled juncture interconnecting the first acoustic wave guide to the second acoustic wave guide; e) a primary acoustic reflector provided in the angled juncture to angularly reflect acoustic waves between the first and second acoustic wave guides; and f) a secondary acoustic reflector positioned to directly reflect an acoustic wave emanating from the acoustic wave transmitter to the acoustic wave receiver. The second acoustic wave guide is provided with a plurality of longitudinally spaced orifices to facilitate ingress of liquid and flow of a cleaning purge gas outwardly of the second acoustic wave guide. A purge gas port is provided in the first acoustic wave guide for injecting purge gas into the system.

I claim: 
     
       1. An acoustic liquid level detector system comprising: a first acoustic wave guide;   an acoustic wave transmitter and an acoustic wave receiver operably associated with the first acoustic wave guide to transfer acoustic waves between, a) the acoustic transmitter and receiver; and b) the first acoustic wave guide;   a second acoustic wave guide;   an angled juncture interconnecting the first acoustic wave guide to the second acoustic wave guide;   a primary acoustic reflector provided to the angled juncture to angularly reflect acoustic waves between the first and second acoustic wave guides; and   a secondary acoustic reflector positioned to directly reflect an acoustic wave emanating from the acoustic wave transmitter to the acoustic wave receiver.   wherein said secondary reflector comprises a feature formed upon the primary reflector.   
     
     
       2. The acoustic liquid level detector system of claim 1 wherein the transmitter and receiver comprise an integrated acoustic wave transceiver. 
     
     
       3. The acoustic liquid level detector system of claim 1 wherein the transmitter and receiver respectively transmit and receive acoustic waves within ultrasonic frequencies. 
     
     
       4. The acoustic liquid level detector system of claim 1 wherein the secondary reflector is positioned within the angled juncture. 
     
     
       5. The acoustic liquid level detector system of claim 1 wherein the primary reflector includes an outer reflective surface, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector. 
     
     
       6. The acoustic liquid level detector system of claim 1 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector has a reflective outer surface which is provided within the angled juncture at about 90° relative to the first longitudinal axis.   
     
     
       7. The acoustic liquid level detector system of claim 1 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector, and the bore having a bore axis which is substantially parallel with the first longitudinal axis.   
     
     
       8. The acoustic liquid level detector system of claim 1 wherein the second acoustic wave guide includes sidewalls having a first longitudinal end portion and a second longitudinal end portion, the first end portion joining with the angled juncture, the second end portion being configured to be placed through an upper level of liquid and including a plurality of longitudinally spaced orifices extending through the sidewalls. 
     
     
       9. The acoustic liquid level detector system of claim 1 further comprising a purge gas port provided in the first acoustic wave guide. 
     
     
       10. An acoustic liquid level detector system comprising: a first acoustic wave guide;   an ultrasonic wave transceiver operably associated with the first acoustic wave guide to transfer ultrasonic waves between the ultrasonic transceiver and the first acoustic wave guide;   a second acoustic wave guide, the second acoustic wave guide including sidewalls having a first longitudinal end portion and a second longitudinal end portion, the first end portion joining with the angled juncture, the second end portion including a plurality of longitudinally spaced fluid communication orifices extending through the sidewalls;   an angled juncture interconnecting the first acoustic wave guide to the second acoustic wave guide;   a primary acoustic reflector provided in the angled juncture to angularly reflect ultrasonic waves between the first and second acoustic wave guides; and   a secondary acoustic reflector positioned to directly reflect an acoustic wave emanating from the acoustic wave transceiver back to the acoustic wave transceiver. wherein the secondary reflector comprises a feature provided upon the primary reflector.     
     
     
       11. The acoustic liquid level detector system of claim 10 wherein the secondary reflector is positioned within the angled juncture. 
     
     
       12. The acoustic liquid level detector system of claim 10 wherein the primary reflector includes an outer reflective surface, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector. 
     
     
       13. The acoustic liquid level detector system of claim 10 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector has a reflective outer surface which is provided within the angled juncture at about 90° relative to the first longitudinal axis.   
     
     
       14. The acoustic liquid level detector system of claim 10 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector, and the bore having a bore axis which is substantially parallel with the first longitudinal axis.   
     
     
       15. The acoustic liquid level detector system of claim 10 further comprising a purge gas port provided in the first acoustic wave guide. 
     
     
       16. An acoustic liquid level detector system comprising: a first acoustic wave guide;   a purge gas port provided in the first acoustic wave guide;   an ultrasonic wave transceiver operably associated with the first acoustic wave guide to transfer ultrasonic waves between the ultrasonic transceiver and the first acoustic wave guide;   a second acoustic wave guide, the second acoustic wave guide including sidewalls having a first longitudinal end portion and a second longitudinal end portion;   an angled juncture interconnecting the first acoustic wave guide to the second acoustic wave guide;   wherein said first end portion joining with the angled juncture, the second end portion including a plurality of longitudinally spaced fluid communication orifices extending through the sidewalls;   a primary acoustic reflector provided in the angled juncture to angularly reflect ultrasonic waves between the first and second acoustic wave guides; and   a secondary acoustic reflector centrally provided upon the primary acoustic reflector within the angled juncture to directly reflect an ultrasonic wave emanating from the ultrasonic transceiver through the first wave guide back into the first wave guide to the ultrasonic transceiver.   
     
     
       17. The acoustic liquid level detector system of claim 16 wherein the primary reflector includes an outer reflective surface, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector. 
     
     
       18. The acoustic liquid level detector system of claim 16 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector has a reflective outer surface which is provided within the angled juncture at about 90° relative to the first longitudinal axis.   
     
     
       19. The acoustic liquid level detector system of claim 16 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector, and the bore having a bore axis which is substantially parallel with the first longitudinal axis.   
     
     
       20. An acoustic liquid level detector system comprising: a first acoustic wave guide;   an acoustic wave transmitter and an acoustic wave receiver operably associated with the first acoustic wave guide to transfer acoustic waves between, a) the acoustic transmitter and receiver; and b) the first acoustic wave guide;   a second acoustic wave guide;   an angled juncture interconnecting the first acoustic wave guide to the second acoustic wave guide;   a primary acoustic reflector provided in the angled juncture to angularly reflect acoustic waves between the first and second acoustic wave guides; and   a second acoustic reflector provided in the angled juncture to reflect an acoustic wave emanating from the acoustic wave transmitter through the first wave guide back into the first wave guide to the acoustic wave receiver; wherein the secondary reflector comprises a feature provided upon the primary reflector.     
     
     
       21. The acoustic liquid level detector system of claim 20 wherein the primary reflector includes an outer reflective surface, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector. 
     
     
       22. The acoustic liquid level detector system of claim 20 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector has a reflective outer surface which is provided within the angled juncture at about 90° relative to the first longitudinal axis.   
     
     
       23. The acoustic liquid level detector system of claim 20 wherein, the first and second acoustic wave guides include respective first and second longitudinal axes, the angled juncture orienting the first and second longitudinal axes relative to one another at about 90°; and   the primary reflector has a reflective outer surface which is provided within the angled juncture at about 45° relative to the first longitudinal axis, and the secondary reflector comprises a feature formed into the primary outer reflective surface, the feature being a bore formed through the outer reflective surface into the primary reflector, and the bore having a bore axis which is substantially parallel with the first longitudinal axis.   
     
     
       24. The acoustic liquid level detector system of claim 20 wherein the second acoustic wave guide includes sidewalls having a first longitudinal end portion and a second longitudinal end portion, the first end portion joining with the angled juncture, the second end portion being configured to be placed through an upper level of liquid and including a plurality of longitudinally spaced orifices extending through the sidewalls. 
     
     
       25. An acoustic liquid level detector system comprising: an acoustic wave transmitter;   at least one longitudinally elongated acoustic wave guide operably associated with the transmitter to receive acoustic waves transmitted therefrom, the acoustic wave guide having sidewalls including a first longitudinal end portion and a second longitudinal end portion, the first end portion being configured to receive acoustic waves from the transmitter and transfer such waves to the second end portion, the second end portion being configured to be placed through an upper level of liquid and including a plurality of longitudinally spaced orifices extending through the sidewalls; and   means for injecting a purge gas into the acoustic wave guide.